1. Technical Field
The present invention relates to a projector that projects moving images being a result of scanning output of a video signal, and a projector screen that displays thereon the moving images by passing through or reflecting projection lights to be emitted when the projector projects the moving images.
2. Related Art
A screen displays moving images being a result of a projector subjecting a video signal to scanning output, and for such a use, there have been various proposals for the aim of increasing the quality of display images. As an example, refer to Patent Document 1 (JP-A-2003-121943).
The screen described in Patent Document 1 indeed provides the quality increase for display images by preventing room lights from being reflected in the images with a variable reflection coefficient. However, the screen is not serving the need at all for controlling or eliminating any possible image blurring that is inherently observed during display of moving images. This image blurring occurs due to the characteristics of moving image display, i.e., frames each have a different image, and a viewer generally keeps looking at the sequence of image frames so that the moving images are perceived. When a viewer looks at such a sequence of image frames, due to the persistence of vision in his or her eye retina, one image looks overlapped with the subsequent image and thus the moving images look blurred, thereby causing blurring of the moving images. The quality degradation due to such blurring of the moving images is totally different from the quality degradation due to room lights reflected in the images. This is the reason why the screen of Patent Document 1 is not serving right to control or eliminate blurring of moving images.
Patent Document 2 (JP-A-2006-106689) also describes the technology of controlling or eliminating blurring of moving images on the side of a device for generating the moving images. With the technology of Patent Document 2, the phenomenon of persistence of vision is prevented by instantaneously displaying a black image of a signal at a fixed level, e.g., at a black level, in the sequence of image frames, thereby aiming to control or eliminate blurring of moving images. In Patent Document 2, although exemplified is a liquid crystal display device, the same is true for a projector in view of deriving moving images. Therefore, by utilizing the technology of Patent Document 2 for generating moving images in a projector, some effects are expected in terms of controlling or eliminating blurring of the moving images displayed by directing projection lights of the projector to a screen.
The issue here is that, in order to deal with any possible blurring of moving images on the side of any existing projector, there needs to establish a matching, in terms of circuit configuration, with other control devices in the projector for use for image generation, thereby requiring the extensive adaptations and circuit change to make. If with any projector recently appeared in the market, there also needs to make design change or facility change in consideration of preventing blurring of moving images.